Re: [PSES] LISN Calibration Measurement Uncertainty
All, As always - thanks for the feedback and discussion. Learn a lot from this forum Best regards, Mac From: Ken Javor To: EMC-PSTC@LISTSERV.IEEE.ORG Sent: Wednesday, September 13, 2017 8:57 AM Subject: Re: [PSES] LISN Calibration Measurement Uncertainty I assumed that since uncertainty was in question, that this was some sort of CISPR 22 or similar quest, so 150 kHz and up, and not CISPR 25. If it were CISPR 25, then it is a low impedance at 150 kHz as Tom points out, but using the technique I suggested, excellent accuracy may still be had. Ken Javor Phone: (256) 650-5261 > From: "T.Sato" > Reply-To: "T.Sato" > Date: Wed, 13 Sep 2017 22:09:36 +0900 > To: > Subject: Re: [PSES] LISN Calibration Measurement Uncertainty > > On Tue, 12 Sep 2017 10:13:26 -0500, > Ken Javor wrote: > >> There shouldn't be a lower impedance issue, because from 150 kHz up the LISN >> is very close to 50 ohms. And once the LISN coil impedance is well above 50 >> ohms, the measured LISN impedance should be 50 ohms in parallel with the >> bleeder resistor, which is essentially 50 ohms. The only affect is if there > ... > > I think: > > o 50 ohms / 50 uH + 5 ohms LISN has impedance spec down to 9 kHz, > and its EUT port impedance is 5 ohms + j2.8 ohms at 9 kHz. > > o Automotive 5 uH LISN has impedance spec down to 150 kHz, and its > EUT port impedance is j4.7 ohms at 150 kHz. > > Regards, > Tom > > -- > Tomonori Sato > URL: http://t-sato.in.coocan.jp > > >>> From: "T.Sato" >>> Reply-To: "T.Sato" >>> Date: Tue, 12 Sep 2017 21:58:54 +0900 >>> To: >>> Subject: Re: [PSES] LISN Calibration Measurement Uncertainty >>> >>> On Mon, 11 Sep 2017 16:32:09 +, >>> Mac Elliott <0a115b29e815-dmarc-requ...@ieee.org> wrote: >>> >>>> We are interested in doing some in-house LISN calibrations (impedance >>>> verification only using network analyzer) and need to develop an >>>> uncertainty >>>> budget. >>>> Does anyone happen to have a budget you could share with us? We will go >>>> through the exercise of calculating ourself but if there is one out there >>>> would appreciate it if you could share. >>> >>> I think the major contributions would be: >>> >>> o network analyzer (VNA?); >>> o calibration jig which will be required to connect coax to the LISN >>> terminals. >>> >>> Other possible contributions such as resolution and repeatability may also >>> need to be considered, even if they are relatively minor. >>> >>> >>> For lower impedance, network analyzers may have relatively large impedance >>> measurement uncertainty: >>> >>> >>> http://www.keysight.com/main/editorial.jspx?cc=ES&lc=spa&ckey=102148:eps >>> g: >>> faq&nid=-11143.0.00&id=102148:epsg:faq >>> >>> Regards, >>> Tom >>> >>> -- >>> Tomonori Sato >>> URL: http://t-sato.in.coocan.jp >>> >>> - >>> >>> This message is from the IEEE Product Safety Engineering Society emc-pstc >>> discussion list. To post a message to the list, send your e-mail to >>> >>> >>> All emc-pstc postings are archived and searchable on the web at: >>> http://www.ieee-pses.org/emc-pstc.html >>> >>> Attachments are not permitted but the IEEE PSES Online Communities site at >>> http://product-compliance.oc.ieee.org/ can be used for graphics (in >>> well-used >>> formats), large files, etc. >>> >>> Website: http://www.ieee-pses.org/ >>> Instructions: http://www.ieee-pses.org/list.html (including how to >>> unsubscribe) >>> List rules: http://www.ieee-pses.org/listrules.html >>> >>> For help, send mail to the list administrators: >>> Scott Douglas >>> Mike Cantwell >>> >>> For policy questions, send mail to: >>> Jim Bacher: >>> David Heald: >> >> - >> >> This message is from the IEEE Product Safety Engineering Society emc-pstc >> discussion list. To post a message to the list, send your e-mail to >> >> >> All emc-pstc postings are archived and searchable on the web at: >> http://www.ieee-pses.org/emc-pstc.html >> >> Attachments are not per
Re: [PSES] LISN Calibration Measurement Uncertainty
I assumed that since uncertainty was in question, that this was some sort of CISPR 22 or similar quest, so 150 kHz and up, and not CISPR 25. If it were CISPR 25, then it is a low impedance at 150 kHz as Tom points out, but using the technique I suggested, excellent accuracy may still be had. Ken Javor Phone: (256) 650-5261 > From: "T.Sato" > Reply-To: "T.Sato" > Date: Wed, 13 Sep 2017 22:09:36 +0900 > To: > Subject: Re: [PSES] LISN Calibration Measurement Uncertainty > > On Tue, 12 Sep 2017 10:13:26 -0500, > Ken Javor wrote: > >> There shouldn't be a lower impedance issue, because from 150 kHz up the LISN >> is very close to 50 ohms. And once the LISN coil impedance is well above 50 >> ohms, the measured LISN impedance should be 50 ohms in parallel with the >> bleeder resistor, which is essentially 50 ohms. The only affect is if there > ... > > I think: > > o 50 ohms / 50 uH + 5 ohms LISN has impedance spec down to 9 kHz, > and its EUT port impedance is 5 ohms + j2.8 ohms at 9 kHz. > > o Automotive 5 uH LISN has impedance spec down to 150 kHz, and its > EUT port impedance is j4.7 ohms at 150 kHz. > > Regards, > Tom > > -- > Tomonori Sato > URL: http://t-sato.in.coocan.jp > > >>> From: "T.Sato" >>> Reply-To: "T.Sato" >>> Date: Tue, 12 Sep 2017 21:58:54 +0900 >>> To: >>> Subject: Re: [PSES] LISN Calibration Measurement Uncertainty >>> >>> On Mon, 11 Sep 2017 16:32:09 +, >>> Mac Elliott <0a115b29e815-dmarc-requ...@ieee.org> wrote: >>> >>>> We are interested in doing some in-house LISN calibrations (impedance >>>> verification only using network analyzer) and need to develop an >>>> uncertainty >>>> budget. >>>> Does anyone happen to have a budget you could share with us? We will go >>>> through the exercise of calculating ourself but if there is one out there >>>> would appreciate it if you could share. >>> >>> I think the major contributions would be: >>> >>> o network analyzer (VNA?); >>> o calibration jig which will be required to connect coax to the LISN >>> terminals. >>> >>> Other possible contributions such as resolution and repeatability may also >>> need to be considered, even if they are relatively minor. >>> >>> >>> For lower impedance, network analyzers may have relatively large impedance >>> measurement uncertainty: >>> >>> >>> http://www.keysight.com/main/editorial.jspx?cc=ES&lc=spa&ckey=102148:eps >>> g: >>> faq&nid=-11143.0.00&id=102148:epsg:faq >>> >>> Regards, >>> Tom >>> >>> -- >>> Tomonori Sato >>> URL: http://t-sato.in.coocan.jp >>> >>> - >>> >>> This message is from the IEEE Product Safety Engineering Society emc-pstc >>> discussion list. To post a message to the list, send your e-mail to >>> >>> >>> All emc-pstc postings are archived and searchable on the web at: >>> http://www.ieee-pses.org/emc-pstc.html >>> >>> Attachments are not permitted but the IEEE PSES Online Communities site at >>> http://product-compliance.oc.ieee.org/ can be used for graphics (in >>> well-used >>> formats), large files, etc. >>> >>> Website: http://www.ieee-pses.org/ >>> Instructions: http://www.ieee-pses.org/list.html (including how to >>> unsubscribe) >>> List rules: http://www.ieee-pses.org/listrules.html >>> >>> For help, send mail to the list administrators: >>> Scott Douglas >>> Mike Cantwell >>> >>> For policy questions, send mail to: >>> Jim Bacher: >>> David Heald: >> >> - >> >> This message is from the IEEE Product Safety Engineering Society emc-pstc >> discussion list. To post a message to the list, send your e-mail to >> >> >> All emc-pstc postings are archived and searchable on the web at: >> http://www.ieee-pses.org/emc-pstc.html >> >> Attachments are not permitted but the IEEE PSES Online Communities site at >> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used >> formats), large files, etc. >> >> Website: http://www.ieee-pses.org/ >> Instructions: http://
Re: [PSES] LISN Calibration Measurement Uncertainty
On Tue, 12 Sep 2017 10:13:26 -0500, Ken Javor wrote: > There shouldn't be a lower impedance issue, because from 150 kHz up the LISN > is very close to 50 ohms. And once the LISN coil impedance is well above 50 > ohms, the measured LISN impedance should be 50 ohms in parallel with the > bleeder resistor, which is essentially 50 ohms. The only affect is if there ... I think: o 50 ohms / 50 uH + 5 ohms LISN has impedance spec down to 9 kHz, and its EUT port impedance is 5 ohms + j2.8 ohms at 9 kHz. o Automotive 5 uH LISN has impedance spec down to 150 kHz, and its EUT port impedance is j4.7 ohms at 150 kHz. Regards, Tom -- Tomonori Sato URL: http://t-sato.in.coocan.jp >> From: "T.Sato" >> Reply-To: "T.Sato" >> Date: Tue, 12 Sep 2017 21:58:54 +0900 >> To: >> Subject: Re: [PSES] LISN Calibration Measurement Uncertainty >> >> On Mon, 11 Sep 2017 16:32:09 +, >> Mac Elliott <0a115b29e815-dmarc-requ...@ieee.org> wrote: >> >>> We are interested in doing some in-house LISN calibrations (impedance >>> verification only using network analyzer) and need to develop an uncertainty >>> budget. >>> Does anyone happen to have a budget you could share with us? We will go >>> through the exercise of calculating ourself but if there is one out there >>> would appreciate it if you could share. >> >> I think the major contributions would be: >> >> o network analyzer (VNA?); >> o calibration jig which will be required to connect coax to the LISN >> terminals. >> >> Other possible contributions such as resolution and repeatability may also >> need to be considered, even if they are relatively minor. >> >> >> For lower impedance, network analyzers may have relatively large impedance >> measurement uncertainty: >> >> >> http://www.keysight.com/main/editorial.jspx?cc=ES&lc=spa&ckey=102148:epsg: >> faq&nid=-11143.0.00&id=102148:epsg:faq >> >> Regards, >> Tom >> >> -- >> Tomonori Sato >> URL: http://t-sato.in.coocan.jp >> >> - >> >> This message is from the IEEE Product Safety Engineering Society emc-pstc >> discussion list. To post a message to the list, send your e-mail to >> >> >> All emc-pstc postings are archived and searchable on the web at: >> http://www.ieee-pses.org/emc-pstc.html >> >> Attachments are not permitted but the IEEE PSES Online Communities site at >> http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used >> formats), large files, etc. >> >> Website: http://www.ieee-pses.org/ >> Instructions: http://www.ieee-pses.org/list.html (including how to >> unsubscribe) >> List rules: http://www.ieee-pses.org/listrules.html >> >> For help, send mail to the list administrators: >> Scott Douglas >> Mike Cantwell >> >> For policy questions, send mail to: >> Jim Bacher: >> David Heald: > > - > > This message is from the IEEE Product Safety Engineering Society emc-pstc > discussion list. To post a message to the list, send your e-mail to > > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieee-pses.org/emc-pstc.html > > Attachments are not permitted but the IEEE PSES Online Communities site at > http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used > formats), large files, etc. > > Website: http://www.ieee-pses.org/ > Instructions: http://www.ieee-pses.org/list.html (including how to > unsubscribe) > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas > Mike Cantwell > > For policy questions, send mail to: > Jim Bacher: > David Heald: - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
Re: [PSES] LISN Calibration Measurement Uncertainty
There shouldn't be a lower impedance issue, because from 150 kHz up the LISN is very close to 50 ohms. And once the LISN coil impedance is well above 50 ohms, the measured LISN impedance should be 50 ohms in parallel with the bleeder resistor, which is essentially 50 ohms. The only affect is if there is a parasitic that tanks with the coil to lower the total impedance to something closer to 50 ohms. That shouldn't be the case down the road if not when acquired, unless the LISN is damaged. So there really shouldn't be an issue here. Also, not familiar with modern VNAs (my HP 4195A has a max output of 15 dBm, or 122 dBuV across 50 ohms), but if I were using a signal generator and a spectrum analyzer, I could use quite high potentials (3 volts or more) and very flat current probe with say 0.1 or 1 ohm transfer impedance, to get numbers well above my noise floor, and a current probe with flat and low transfer impedance is very accurate because the value depends not on the construction of the probe but on the loading resistance, which is much easier to get to a specific value, just like the 50 ohms of the LISN has been noted in this thread to not be part of the LISN construction, but the load placed on it by a spectrum analyze or a dummy load of great precision. And the spectrum analyzer as a load must have at least 10 dB internal or external attenuation selected in order to give assurance that it looks like 50 ohms. Ken Javor Phone: (256) 650-5261 > From: "T.Sato" > Reply-To: "T.Sato" > Date: Tue, 12 Sep 2017 21:58:54 +0900 > To: > Subject: Re: [PSES] LISN Calibration Measurement Uncertainty > > On Mon, 11 Sep 2017 16:32:09 +, > Mac Elliott <0a115b29e815-dmarc-requ...@ieee.org> wrote: > >> We are interested in doing some in-house LISN calibrations (impedance >> verification only using network analyzer) and need to develop an uncertainty >> budget. >> Does anyone happen to have a budget you could share with us? We will go >> through the exercise of calculating ourself but if there is one out there >> would appreciate it if you could share. > > I think the major contributions would be: > > o network analyzer (VNA?); > o calibration jig which will be required to connect coax to the LISN > terminals. > > Other possible contributions such as resolution and repeatability may also > need to be considered, even if they are relatively minor. > > > For lower impedance, network analyzers may have relatively large impedance > measurement uncertainty: > > > http://www.keysight.com/main/editorial.jspx?cc=ES&lc=spa&ckey=102148:epsg: > faq&nid=-11143.0.00&id=102148:epsg:faq > > Regards, > Tom > > -- > Tomonori Sato > URL: http://t-sato.in.coocan.jp > > - > > This message is from the IEEE Product Safety Engineering Society emc-pstc > discussion list. To post a message to the list, send your e-mail to > > > All emc-pstc postings are archived and searchable on the web at: > http://www.ieee-pses.org/emc-pstc.html > > Attachments are not permitted but the IEEE PSES Online Communities site at > http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used > formats), large files, etc. > > Website: http://www.ieee-pses.org/ > Instructions: http://www.ieee-pses.org/list.html (including how to > unsubscribe) > List rules: http://www.ieee-pses.org/listrules.html > > For help, send mail to the list administrators: > Scott Douglas > Mike Cantwell > > For policy questions, send mail to: > Jim Bacher: > David Heald: - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
Re: [PSES] LISN Calibration Measurement Uncertainty
On Mon, 11 Sep 2017 16:32:09 +, Mac Elliott <0a115b29e815-dmarc-requ...@ieee.org> wrote: > We are interested in doing some in-house LISN calibrations (impedance > verification only using network analyzer) and need to develop an uncertainty > budget. > Does anyone happen to have a budget you could share with us? We will go > through the exercise of calculating ourself but if there is one out there > would appreciate it if you could share. I think the major contributions would be: o network analyzer (VNA?); o calibration jig which will be required to connect coax to the LISN terminals. Other possible contributions such as resolution and repeatability may also need to be considered, even if they are relatively minor. For lower impedance, network analyzers may have relatively large impedance measurement uncertainty: http://www.keysight.com/main/editorial.jspx?cc=ES&lc=spa&ckey=102148:epsg:faq&nid=-11143.0.00&id=102148:epsg:faq Regards, Tom -- Tomonori Sato URL: http://t-sato.in.coocan.jp - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
Re: [PSES] LISN Calibration Measurement Uncertainty
I'm afraid that one cannot assume that our ancestors were either all-knowing or idiots. They were people, just like us, and they got it right mostly, but not always. With best wishes DESIGN IT IN! OOO - Own Opinions Only www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England UK is a sovereignty, not a Zollverein-ty -Original Message- From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Tuesday, September 12, 2017 12:37 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty Perhaps all that is needed is to know is the Insertion Loss of the LISN. Some manufacturers provide this for every s/n. The LISN is only there to provide a known impedance to the source of emission so that RF current can be measured with repeatability. I do understand that CM and DM currents will have different (and unknown) source impedance and that those impedances will be a function of frequency, but I feel that's beside the point. I have to assume the folks at CISPR understood those topics and that they likely deliberated long and hard and did lots of measurements both in the lab and in the field before agreeing on the LISN as a standard transducer for the evaluation of conducted RF emission. If there were something fundamentally wrong with the method of measurement, I suspect it would have been uncovered long ago. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Monday, September 11, 2017 4:10 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty The point of the cm vs. dm discussion is that the effect of LISN impedance is not so important for dm as for cm, speaking very generally, so that the effect of uncertainty in LISN impedance on dm emissions is less than for cm. But we don't separately measure cm and dm, so we don't know, looking at any specific signal, what the uncertainty is, even if we have nailed down the uncertainty of the LISN impedance. And you don't need two LISNs to separate modes, but that is another discussion. Ken Javor Phone: (256) 650-5261 - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald: - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
Re: [PSES] LISN Calibration Measurement Uncertainty
No criticism of how a LISN is calibrated. That wasn't the point. The point was that LISN impedance uncertainty affects the measurement of conducted emissions differently by mode, so that the overall uncertainty of the measurement of CE is different from that of the LISN impedance. Also, while the point of a 50 uH LISN is in fact to provide that impedance, the original limit was based on the rf susceptibility of radios operating below 30 MHz, and that susceptibility was to the rf potential caused by various electronic loads. It wasn't about current at all. Ken Javor Phone: (256) 650-5261 > From: Ralph McDiarmid > Date: Mon, 11 Sep 2017 23:36:35 + > To: Ken Javor , "EMC-PSTC@LISTSERV.IEEE.ORG" > > Conversation: [PSES] LISN Calibration Measurement Uncertainty > Subject: RE: [PSES] LISN Calibration Measurement Uncertainty > > Perhaps all that is needed is to know is the Insertion Loss of the LISN. Some > manufacturers provide this for every s/n. > > The LISN is only there to provide a known impedance to the source of emission > so that RF current can be measured with repeatability. I do understand that > CM and DM currents will have different (and unknown) source impedance and that > those impedances will be a function of frequency, but I feel that's beside the > point. > > I have to assume the folks at CISPR understood those topics and that they > likely deliberated long and hard and did lots of measurements both in the lab > and in the field before agreeing on the LISN as a standard transducer for the > evaluation of conducted RF emission. > > If there were something fundamentally wrong with the method of measurement, I > suspect it would have been uncovered long ago. > > Ralph McDiarmid > Product Compliance > Engineering > Solar Business > Schneider Electric > > > From: Ken Javor [mailto:ken.ja...@emccompliance.com] > Sent: Monday, September 11, 2017 4:10 PM > To: EMC-PSTC@LISTSERV.IEEE.ORG > Subject: Re: [PSES] LISN Calibration Measurement Uncertainty > > The point of the cm vs. dm discussion is that the effect of LISN impedance is > not so important for dm as for cm, speaking very generally, so that the effect > of uncertainty in LISN impedance on dm emissions is less than for cm. But we > don't separately measure cm and dm, so we don't know, looking at any specific > signal, what the uncertainty is, even if we have nailed down the uncertainty > of the LISN impedance. And you don't need two LISNs to separate modes, but > that is another discussion. > > > Ken Javor > Phone: (256) 650-5261 > - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
Re: [PSES] LISN Calibration Measurement Uncertainty
Perhaps all that is needed is to know is the Insertion Loss of the LISN. Some manufacturers provide this for every s/n. The LISN is only there to provide a known impedance to the source of emission so that RF current can be measured with repeatability. I do understand that CM and DM currents will have different (and unknown) source impedance and that those impedances will be a function of frequency, but I feel that's beside the point. I have to assume the folks at CISPR understood those topics and that they likely deliberated long and hard and did lots of measurements both in the lab and in the field before agreeing on the LISN as a standard transducer for the evaluation of conducted RF emission. If there were something fundamentally wrong with the method of measurement, I suspect it would have been uncovered long ago. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Monday, September 11, 2017 4:10 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty The point of the cm vs. dm discussion is that the effect of LISN impedance is not so important for dm as for cm, speaking very generally, so that the effect of uncertainty in LISN impedance on dm emissions is less than for cm. But we don't separately measure cm and dm, so we don't know, looking at any specific signal, what the uncertainty is, even if we have nailed down the uncertainty of the LISN impedance. And you don't need two LISNs to separate modes, but that is another discussion. Ken Javor Phone: (256) 650-5261 - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
Re: [PSES] LISN Calibration Measurement Uncertainty
The point of the cm vs. dm discussion is that the effect of LISN impedance is not so important for dm as for cm, speaking very generally, so that the effect of uncertainty in LISN impedance on dm emissions is less than for cm. But we don't separately measure cm and dm, so we don't know, looking at any specific signal, what the uncertainty is, even if we have nailed down the uncertainty of the LISN impedance. And you don't need two LISNs to separate modes, but that is another discussion. Ken Javor Phone: (256) 650-5261 > From: Ralph McDiarmid > Reply-To: Ralph McDiarmid > Date: Mon, 11 Sep 2017 22:32:14 + > To: > Conversation: [PSES] LISN Calibration Measurement Uncertainty > Subject: Re: [PSES] LISN Calibration Measurement Uncertainty > > Sorry, I guess we drifted a little off topic, and that's my fault. If you > want to characterize a LISN for the purpose of defining an measurement > "uncertainty budget" then I suppose all that is needed is a carefully written > test procedure. I doubt a Network Analyzer is required, I think a signal > generator and a scope would suffice. > > What parameter of a LISN matters for determining its measurement uncertainty? > I can only think of the impedance "seen" the DUT. As the impedance gradually > moves away from the ideal 50 ohm resistive, then I think less signal reaches > the EMI receiver, and that is the "uncertainty" or maybe error is a better > term. I really cannot see how CM vs DM comes into play at all; the LISN > measures both as far as I know, so one cannot separate the two, without using > a second LISN connected to a second power pole of the DUT. I think save to > say that most DUTs will have a least two power poles, a "line" and a "neutral > for connection to the a.c. mains. > > I think some manufactures provide a graph or two plotting something (perhaps > insertion loss versus frequency) for that serial number. > > I hope that helped a little. > > Ralph McDiarmid > Product Compliance > Engineering > Solar Business > Schneider Electric > > > -Original Message- > From: John Woodgate [mailto:jmw1...@btinternet.com] > Sent: Monday, September 11, 2017 1:28 PM > To: Ralph McDiarmid ; > EMC-PSTC@LISTSERV.IEEE.ORG > Subject: RE: [PSES] LISN Calibration Measurement Uncertainty > > It's not quite as simple as it may appear. Mr Javor points out that it > measures two mixtures of DM and CM voltages, which is not helpful either in > fixing a design or in determining the consequent radiated emission (due to the > CM component alone). > > The 50 ohms is indeed the input resistance of the SA. But it's not necessarily > (not likely to be) the impedance looking back down the mains lead to the EUT. > All it does is to help produce consistent results, it doesn't do anything to > help the results to be representative of real world conditions. > > With best wishes DESIGN IT IN! OOO - Own Opinions Only www.jmwa.demon.co.uk J > M Woodgate and Associates Rayleigh England > > UK is a sovereignty, not a Zollverein-ty > > -Original Message- > From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] > Sent: Monday, September 11, 2017 7:33 PM > To: EMC-PSTC@LISTSERV.IEEE.ORG > Subject: Re: [PSES] LISN Calibration Measurement Uncertainty > > My understanding: > > A LISN seems to be a simple device, which has three ports: an input, an > output, and a sense port. The sense port connects to the spectrum analyzer or > EMI receiver, with the input port connecting to mains, and the output port > connecting to the power terminals of the device under test (DUT). > > What impedance is important? I assume it is that impedance which is "seen" > by the DUT when it is connected to the output port of the LISN. I think it is > that impedance which is 'stabilized' over a given bandwidth for the purpose of > a repeatable measurement environment. > > When we talk about a "50 ohm LISN", isn't it the EMI receiver that provides > the 50 ohms? Both above and below the design bandwidth of the LISN (AMN), > there will be reactance (inductive or capacitive) that begins to affect the > impedance seen by the DUT, which moves the load impedance further away from > the ideal 50 ohms. > > > Ralph McDiarmid > Product Compliance > Engineering > Solar Business > Schneider Electric > > > From: Ken Javor [mailto:ken.ja...@emccompliance.com] > Sent: Monday, September 11, 2017 10:21 AM > To: EMC-PSTC@LISTSERV.IEEE.ORG > Subject: Re: [PSES] LISN Calibration Measurement Uncertainty > > Off-topic response. Grinding an axe. Clearly the network analyzer itself
Re: [PSES] LISN Calibration Measurement Uncertainty
Sorry, I guess we drifted a little off topic, and that's my fault. If you want to characterize a LISN for the purpose of defining an measurement "uncertainty budget" then I suppose all that is needed is a carefully written test procedure. I doubt a Network Analyzer is required, I think a signal generator and a scope would suffice. What parameter of a LISN matters for determining its measurement uncertainty? I can only think of the impedance "seen" the DUT. As the impedance gradually moves away from the ideal 50 ohm resistive, then I think less signal reaches the EMI receiver, and that is the "uncertainty" or maybe error is a better term. I really cannot see how CM vs DM comes into play at all; the LISN measures both as far as I know, so one cannot separate the two, without using a second LISN connected to a second power pole of the DUT. I think save to say that most DUTs will have a least two power poles, a "line" and a "neutral for connection to the a.c. mains. I think some manufactures provide a graph or two plotting something (perhaps insertion loss versus frequency) for that serial number. I hope that helped a little. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric -Original Message- From: John Woodgate [mailto:jmw1...@btinternet.com] Sent: Monday, September 11, 2017 1:28 PM To: Ralph McDiarmid ; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] LISN Calibration Measurement Uncertainty It's not quite as simple as it may appear. Mr Javor points out that it measures two mixtures of DM and CM voltages, which is not helpful either in fixing a design or in determining the consequent radiated emission (due to the CM component alone). The 50 ohms is indeed the input resistance of the SA. But it's not necessarily (not likely to be) the impedance looking back down the mains lead to the EUT. All it does is to help produce consistent results, it doesn't do anything to help the results to be representative of real world conditions. With best wishes DESIGN IT IN! OOO - Own Opinions Only www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England UK is a sovereignty, not a Zollverein-ty -Original Message- From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Monday, September 11, 2017 7:33 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty My understanding: A LISN seems to be a simple device, which has three ports: an input, an output, and a sense port. The sense port connects to the spectrum analyzer or EMI receiver, with the input port connecting to mains, and the output port connecting to the power terminals of the device under test (DUT). What impedance is important? I assume it is that impedance which is "seen" by the DUT when it is connected to the output port of the LISN. I think it is that impedance which is 'stabilized' over a given bandwidth for the purpose of a repeatable measurement environment. When we talk about a "50 ohm LISN", isn't it the EMI receiver that provides the 50 ohms? Both above and below the design bandwidth of the LISN (AMN), there will be reactance (inductive or capacitive) that begins to affect the impedance seen by the DUT, which moves the load impedance further away from the ideal 50 ohms. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Monday, September 11, 2017 10:21 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty Off-topic response. Grinding an axe. Clearly the network analyzer itself serves as a limit on the achievable uncertainty, but it should be much better than what is needed (+/-20% in the military world). That aside, consider that differential mode emissions tend to be low impedance relative to that of the LISN, and therefore act as voltage sources, whose amplitude doesn't correspond much to changes in LISN amplitude. Common mode emissions tend to be current sources and therefore common mode emission amplitudes track closely with changes in LISN impedance. But we don't measure these modes separately, but rather as vector sums on the phase conductor, and vector differences on neutral, so we have no idea what the effect of the LISN impedance on any particular emission measured actually is. Ken Javor Phone: (256) 650-5261 From: Mac Elliott <mailto:0a115b29e815-dmarc-requ...@ieee.org> Reply-To: Mac Elliott <mailto:mac_elli...@yahoo.com> Date: Mon, 11 Sep 2017 16:32:09 + To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: [PSES] LISN Calibration Measurement Uncertainty All, We are interested in doing some in-house LISN calibrations (impedance verification only using
Re: [PSES] LISN Calibration Measurement Uncertainty
I agree that the AMN (LISN) is intended only to provide consistent (more or less) results, not to represent a real-world impedance at RF. I don't know how much that impedance changes from site to site; quite a lot I'll bet. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric -Original Message- From: John Woodgate [mailto:jmw1...@btinternet.com] Sent: Monday, September 11, 2017 1:28 PM To: Ralph McDiarmid ; EMC-PSTC@LISTSERV.IEEE.ORG Subject: RE: [PSES] LISN Calibration Measurement Uncertainty It's not quite as simple as it may appear. Mr Javor points out that it measures two mixtures of DM and CM voltages, which is not helpful either in fixing a design or in determining the consequent radiated emission (due to the CM component alone). The 50 ohms is indeed the input resistance of the SA. But it's not necessarily (not likely to be) the impedance looking back down the mains lead to the EUT. All it does is to help produce consistent results, it doesn't do anything to help the results to be representative of real world conditions. With best wishes DESIGN IT IN! OOO - Own Opinions Only www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England UK is a sovereignty, not a Zollverein-ty -Original Message- From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Monday, September 11, 2017 7:33 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty My understanding: A LISN seems to be a simple device, which has three ports: an input, an output, and a sense port. The sense port connects to the spectrum analyzer or EMI receiver, with the input port connecting to mains, and the output port connecting to the power terminals of the device under test (DUT). What impedance is important? I assume it is that impedance which is "seen" by the DUT when it is connected to the output port of the LISN. I think it is that impedance which is 'stabilized' over a given bandwidth for the purpose of a repeatable measurement environment. When we talk about a "50 ohm LISN", isn't it the EMI receiver that provides the 50 ohms? Both above and below the design bandwidth of the LISN (AMN), there will be reactance (inductive or capacitive) that begins to affect the impedance seen by the DUT, which moves the load impedance further away from the ideal 50 ohms. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Monday, September 11, 2017 10:21 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty Off-topic response. Grinding an axe. Clearly the network analyzer itself serves as a limit on the achievable uncertainty, but it should be much better than what is needed (+/-20% in the military world). That aside, consider that differential mode emissions tend to be low impedance relative to that of the LISN, and therefore act as voltage sources, whose amplitude doesn't correspond much to changes in LISN amplitude. Common mode emissions tend to be current sources and therefore common mode emission amplitudes track closely with changes in LISN impedance. But we don't measure these modes separately, but rather as vector sums on the phase conductor, and vector differences on neutral, so we have no idea what the effect of the LISN impedance on any particular emission measured actually is. Ken Javor Phone: (256) 650-5261 From: Mac Elliott <mailto:0a115b29e815-dmarc-requ...@ieee.org> Reply-To: Mac Elliott <mailto:mac_elli...@yahoo.com> Date: Mon, 11 Sep 2017 16:32:09 + To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: [PSES] LISN Calibration Measurement Uncertainty All, We are interested in doing some in-house LISN calibrations (impedance verification only using network analyzer) and need to develop an uncertainty budget. Does anyone happen to have a budget you could share with us? We will go through the exercise of calculating ourself but if there is one out there would appreciate it if you could share. Have a great day Mac Elliott - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <mailto:emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) http://www.ieee-pses.org/list.
Re: [PSES] LISN Calibration Measurement Uncertainty
It's not quite as simple as it may appear. Mr Javor points out that it measures two mixtures of DM and CM voltages, which is not helpful either in fixing a design or in determining the consequent radiated emission (due to the CM component alone). The 50 ohms is indeed the input resistance of the SA. But it's not necessarily (not likely to be) the impedance looking back down the mains lead to the EUT. All it does is to help produce consistent results, it doesn't do anything to help the results to be representative of real world conditions. With best wishes DESIGN IT IN! OOO – Own Opinions Only www.jmwa.demon.co.uk J M Woodgate and Associates Rayleigh England UK is a sovereignty, not a Zollverein-ty -Original Message- From: Ralph McDiarmid [mailto:ralph.mcdiar...@schneider-electric.com] Sent: Monday, September 11, 2017 7:33 PM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty My understanding: A LISN seems to be a simple device, which has three ports: an input, an output, and a sense port. The sense port connects to the spectrum analyzer or EMI receiver, with the input port connecting to mains, and the output port connecting to the power terminals of the device under test (DUT). What impedance is important? I assume it is that impedance which is "seen" by the DUT when it is connected to the output port of the LISN. I think it is that impedance which is 'stabilized' over a given bandwidth for the purpose of a repeatable measurement environment. When we talk about a "50 ohm LISN", isn't it the EMI receiver that provides the 50 ohms? Both above and below the design bandwidth of the LISN (AMN), there will be reactance (inductive or capacitive) that begins to affect the impedance seen by the DUT, which moves the load impedance further away from the ideal 50 ohms. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Monday, September 11, 2017 10:21 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty Off-topic response. Grinding an axe. Clearly the network analyzer itself serves as a limit on the achievable uncertainty, but it should be much better than what is needed (+/-20% in the military world). That aside, consider that differential mode emissions tend to be low impedance relative to that of the LISN, and therefore act as voltage sources, whose amplitude doesn't correspond much to changes in LISN amplitude. Common mode emissions tend to be current sources and therefore common mode emission amplitudes track closely with changes in LISN impedance. But we don't measure these modes separately, but rather as vector sums on the phase conductor, and vector differences on neutral, so we have no idea what the effect of the LISN impedance on any particular emission measured actually is. Ken Javor Phone: (256) 650-5261 From: Mac Elliott <mailto:0a115b29e815-dmarc-requ...@ieee.org> Reply-To: Mac Elliott <mailto:mac_elli...@yahoo.com> Date: Mon, 11 Sep 2017 16:32:09 + To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: [PSES] LISN Calibration Measurement Uncertainty All, We are interested in doing some in-house LISN calibrations (impedance verification only using network analyzer) and need to develop an uncertainty budget. Does anyone happen to have a budget you could share with us? We will go through the exercise of calculating ourself but if there is one out there would appreciate it if you could share. Have a great day Mac Elliott - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <mailto:emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <mailto:sdoug...@ieee.org> Mike Cantwell <mailto:mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <mailto:j.bac...@ieee.org> David Heald <mailto:dhe...@gmail.com> __ This email has been scanned by the Symantec Email Security.cloud service. __ - -
Re: [PSES] LISN Calibration Measurement Uncertainty
My understanding: A LISN seems to be a simple device, which has three ports: an input, an output, and a sense port. The sense port connects to the spectrum analyzer or EMI receiver, with the input port connecting to mains, and the output port connecting to the power terminals of the device under test (DUT). What impedance is important? I assume it is that impedance which is "seen" by the DUT when it is connected to the output port of the LISN. I think it is that impedance which is 'stabilized' over a given bandwidth for the purpose of a repeatable measurement environment. When we talk about a "50 ohm LISN", isn't it the EMI receiver that provides the 50 ohms? Both above and below the design bandwidth of the LISN (AMN), there will be reactance (inductive or capacitive) that begins to affect the impedance seen by the DUT, which moves the load impedance further away from the ideal 50 ohms. Ralph McDiarmid Product Compliance Engineering Solar Business Schneider Electric From: Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Monday, September 11, 2017 10:21 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Measurement Uncertainty Off-topic response. Grinding an axe. Clearly the network analyzer itself serves as a limit on the achievable uncertainty, but it should be much better than what is needed (+/-20% in the military world). That aside, consider that differential mode emissions tend to be low impedance relative to that of the LISN, and therefore act as voltage sources, whose amplitude doesn't correspond much to changes in LISN amplitude. Common mode emissions tend to be current sources and therefore common mode emission amplitudes track closely with changes in LISN impedance. But we don't measure these modes separately, but rather as vector sums on the phase conductor, and vector differences on neutral, so we have no idea what the effect of the LISN impedance on any particular emission measured actually is. Ken Javor Phone: (256) 650-5261 From: Mac Elliott <mailto:0a115b29e815-dmarc-requ...@ieee.org> Reply-To: Mac Elliott <mailto:mac_elli...@yahoo.com> Date: Mon, 11 Sep 2017 16:32:09 + To: <mailto:EMC-PSTC@LISTSERV.IEEE.ORG> Subject: [PSES] LISN Calibration Measurement Uncertainty All, We are interested in doing some in-house LISN calibrations (impedance verification only using network analyzer) and need to develop an uncertainty budget. Does anyone happen to have a budget you could share with us? We will go through the exercise of calculating ourself but if there is one out there would appreciate it if you could share. Have a great day Mac Elliott - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <mailto:emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <mailto:sdoug...@ieee.org> Mike Cantwell <mailto:mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <mailto:j.bac...@ieee.org> David Heald <mailto:dhe...@gmail.com> __ This email has been scanned by the Symantec Email Security.cloud service. __ - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <mailto:emc-p...@ieee.org> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <mailto:sdoug...@ieee.org> Mike Cantwell <mailto:mcantw...@ieee.org> For policy questions, send mail to: Jim Bacher <mailto:j.bac...@ieee.org> David Heald <mailto:dhe...@gmail.com> - ---
Re: [PSES] LISN Calibration Measurement Uncertainty
Off-topic response. Grinding an axe. Clearly the network analyzer itself serves as a limit on the achievable uncertainty, but it should be much better than what is needed (+/-20% in the military world). That aside, consider that differential mode emissions tend to be low impedance relative to that of the LISN, and therefore act as voltage sources, whose amplitude doesn¹t correspond much to changes in LISN amplitude. Common mode emissions tend to be current sources and therefore common mode emission amplitudes track closely with changes in LISN impedance. But we don¹t measure these modes separately, but rather as vector sums on the phase conductor, and vector differences on neutral, so we have no idea what the effect of the LISN impedance on any particular emission measured actually is. Ken Javor Phone: (256) 650-5261 From: Mac Elliott <0a115b29e815-dmarc-requ...@ieee.org> Reply-To: Mac Elliott Date: Mon, 11 Sep 2017 16:32:09 + To: Subject: [PSES] LISN Calibration Measurement Uncertainty All, We are interested in doing some in-house LISN calibrations (impedance verification only using network analyzer) and need to develop an uncertainty budget. Does anyone happen to have a budget you could share with us? We will go through the exercise of calculating ourself but if there is one out there would appreciate it if you could share. Have a great day Mac Elliott - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) <http://www.ieee-pses.org/list.html> List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher David Heald - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
[PSES] LISN Calibration Measurement Uncertainty
All, We are interested in doing some in-house LISN calibrations (impedance verification only using network analyzer) and need to develop an uncertainty budget. Does anyone happen to have a budget you could share with us? We will go through the exercise of calculating ourself but if there is one out there would appreciate it if you could share. Have a great day Mac Elliott - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
RE: [PSES] LISN Calibration
From: emc-p...@ieee.org [mailto:emc-p...@ieee.org] On Behalf Of Ken Wyatt Sent: Tuesday, February 10, 2009 11:02 AM To: John Woodgate Cc: EMC-PSTC@LISTSERV.IEEE.ORG Subject: Re: [PSES] LISN Calibration Hi John & Grace, Interesting you should bring this up. I worked for Agilent for over 20 years as their senior EMC engineer before retiring to consult in EMC. I'm currently working on an "EMC Measurements" seminar under contract with Silent Solutions, an EMC consultancy based in New Hampshire. I'll be covering the details of EMC testing, plus verification testing, oriented for the EMC engineer or technician. They are planning on releasing this new seminar (along with their normal EMC offerings) in Chelmsford, MA, the week of May 4th. For additional information, please contact Lee Hill at www.silent-solutions.com. Regards, Ken -- Ken Wyatt Woodland Park, CO Email: k...@emc-seminars.com Web: www.emc-seminars.com Ken: I would hazard a guess, based on what I have seen and my own experiences, that most EMC engineers are not well acquainted with network analyzers. It took me a long time before I grudgingly came around to understand that a network analyzer could be a lot more elegant solution to certain EMC tasks (calibration of current probes, filter characterizations, resonance studies) than a discrete signal sweeper and a spectrum analyzer. Try to work some elementary NA tasks into your seminar. Ed Price ed.pr...@cubic.com mailto:ed.pr...@cubic.com> WB6WSN NARTE Certified EMC Engineer Electromagnetic Compatibility Lab Cubic Defense Applications San Diego, CA USA 858-505-2780 Military & Avionics EMC Is Our Specialty - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher David Heald
Re: [PSES] LISN Calibration
Hi John & Grace, Interesting you should bring this up. I worked for Agilent for over 20 years as their senior EMC engineer before retiring to consult in EMC. I'm currently working on an "EMC Measurements" seminar under contract with Silent Solutions, an EMC consultancy based in New Hampshire. I'll be covering the details of EMC testing, plus verification testing, oriented for the EMC engineer or technician. They are planning on releasing this new seminar (along with their normal EMC offerings) in Chelmsford, MA, the week of May 4th. For additional information, please contact Lee Hill at www.silent-solutions.com. Regards, Ken Ken Wyatt Woodland Park, CO Email: k...@emc-seminars.com Web: www.emc-seminars.com On Feb 10, 2009, at 11:27 AM, John Woodgate wrote: In message << a href="mailto:2a93eb060 02101014h30c866f3h366f5d6fc2253075@mail gmail.com">2a93eb060902101014h30c866f3h366f5d6fc2253...@mail.gmail.com>, dated Tue, 10 Feb 2009, Grace Lin writes: Due to the current ecomonic downturn, it is not easy to obtain an approval for an out of state training. If I were Agilent, I'd realise that and run training sessions in large centres such as NYC. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk Things can always get better. But that's not the only option. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher David Heald
Re: LISN Calibration
In message <2a93eb060902101014h30c866f3h366f5d6fc2253...@mail.gmail.com>, dated Tue, 10 Feb 2009, Grace Lin writes: >Due to the current ecomonic downturn, it is not easy to obtain an >approval for an out of state training. If I were Agilent, I'd realise that and run training sessions in large centres such as NYC. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk Things can always get better. But that's not the only option. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher: David Heald:
Re: LISN Calibration
Dear John, Thank you so much for teaching me. I will keep your suggestion (fix a training session with Agilent) on my wish list. I did browse Agilent's training courses yesterday. Due to the current ecomonic downturn, it is not easy to obtain an approval for an out of state training. Instead, online resources become handy. Agilent has online video demo (such as http://wireless.agilent.com/networkanalyzers/enademo.htm). I started viewing the "Network Analyzer Basics" demo and had to finish it later on. To perform measurement, I have my experienced RF design colleague (who's office is 50 feet from mine) show me the first time. I ask him questions when I feel something is not right. Best regards, Grace On 2/9/09, John Woodgate wrote: In message <2a93eb060902091158v1946f9d1ye54dc2862aea9...@mail.gmail.com>, dated Mon, 9 Feb 2009, Grace Lin writes: I have learned from members that ANSI C63.4 and CISPR 16-1-2 are the calibration standards for LISN for my daily measurement. I have one of my two LISNs ship out last week to an accredited calibration lab. I wonder if I need to ship out the other one for calibration since the second one is used for support equipment. I would strongly advise it. I have found strange differences in results with two apparently good LISNs. This may be why the CISPR 16-1-2 requirements have been made more detailed over the past few years. Is it sufficient that I verify it in-house? If yes, I would need your help with calibration. It's always worth knowing how to do it. I study A.8 of CISPR 16-1-2 Edition 1.2 and Annex E of ANSI C63.4-2003 this morning. Here are my questions: 1. The title of A.8 is "Measurement of the voltage division factor of an artificial mains V-network". What does "voltage division factor"? Does it mean insertion loss? Not exactly; it's the ratio of input voltage, at the connector supplying mains power to the EUT to output voltage at the connector for the measuring receiver. Differences in the impedances at these points are not taken into account, so the ratio is not 'insertion loss' as normally defined. A.8 was written by someone who knew the subject very well, so well that it can be very difficult for others to understand. And the requirement for voltage division factor is 'hidden' in the caption of Figure 4.10. 2. Is the adapter, mentioned in Figure A.6a, Figure A.6b of CISPR 16-1-2 and Figure E.1(a) of ANSI C63.4, commercially available? I don't know: I've made mine myself. If not, is there any guidelines to make it (type of connectors, size and length of wires/cables, etc.)? I think there is no need to be extremely meticulous about this. Whatever mains connector you use, it is not matched to 50 ohms or anything else, but it is electrically 'short' (compared with a wavelength) even at 30 MHz, so it has little effect. Just keep all connections short and rigid (movement of connections can impair repeatability). Should I take a pin from a power plug and solder one end to a SMA receptacle? No. The connections in Figure A6a are **coaxial cables**, so that isn't a single connection to L1 but a coaxial connection to L1 and ground. If yes, is there any preference for the type of the receptacle (cable jack, panel jack, bulkhead, etc. http://www.a phenolrf.com/Products/CatalogPages/sma_catalog.pdf)? Just keep the wires short and rigid, if the connection is not coax. I have, for example, mounted two BNC connectors (L1/ground and N/ground) directly on a metal plate attached to the cover of a UK 13 A plug. I also have a single BNC connected by a short (100 mm)50 ohm coax to a 13 A plug. Inside the plug is a network of five 82 ohm resistors. One goes from each power pin to the ground pin. The other three are connected as a delta, one apex to each power pin, and the third to the incoming coax inner. The outer of the coax goes to ground, of course. This gives an input impedance close to 50 ohms, and 30 ohms between power pins and from each power pin to ground (network alone; no generator connected). The insertion loss is 11.2 dB. I don't remember whether someone told me about this arrangement or whether I invented it. With this device, you can look at both outputs of the LISN at once, if the switching allows you access to both outputs simultaneously (as, in my opinion, it should) for direct comparison purposes. 3. How do I terminate the mains port? The LISN, Solar 9252-50-R-24-N (same as 9252-50-R-24-BNC exc
Re: LISN Calibration
Dear Grace, This freely accessible document may probably help you: http://www.elmac.co.uk/pdfs/ff26_report.pdf Best regards, Orazio - Original Message - From: Grace Lin <mailto:graceli...@gmail.com> To: emc-p...@ieee.org Sent: Monday, February 09, 2009 8:58 PM Subject: LISN Calibration Dear Members, I have learned from members that ANSI C63.4 and CISPR 16-1-2 are the calibration standards for LISN for my daily measurement. I have one of my two LISNs ship out last week to an accredited calibration lab. I wonder if I need to ship out the other one for calibration since the second one is used for support equipment. Is it sufficient that I verify it in-house? If yes, I would need your help with calibration. I study A.8 of CISPR 16-1-2 Edition 1.2 and Annex E of ANSI C63.4-2003 this morning. Here are my questions: 1. The title of A.8 is "Measurement of the voltage division factor of an artificial mains V-network". What does "voltage division factor"? Does it mean insertion loss? 2. Is the adapter, mentioned in Figure A.6a, Figure A.6b of CISPR 16-1-2 and Figure E.1(a) of ANSI C63.4, commercially available? If not, is there any guidelines to make it (type of connectors, size and length of wires/cables, etc.)? Should I take a pin from a power plug and solder one end to a SMA receptacle? If yes, is there any preference for the type of the receptacle (cable jack, panel jack, bulkhead, etc. http://www.amphenolrf.com/Products/CatalogPages/sma_catalog.pdf)? 3. How do I terminate the mains port? The LISN, Solar 9252-50-R-24-N (same as 9252-50-R-24-BNC except with N connector) comes with a permanent attached power cord. Should I pick up a receptable (no wire attached) and connect 50 ohms resistor to L and N respectively, and connect the other end of the resistors to ground reference? 4. Is there any requirement (VSWR etc.) for the 50 ohms terminator? 5. Is 10 dB pads needed? Figure A.6a and Figure A.6b of CISPR 16-1-2 show them. The NOTE from Figure E.1(b) states "Attenuator pads not used with network analyzer. 6. Figure A.6a and Figure A.6b of CISPR 16-1-2 show two ports of network analyzer are used. Figure E.1(b) shows three ports of network analyzer are used. The vector network analyzer I have access to comes with four ports (http://www.home.agilent.com/agilent/pr duct.jspx?cc=US&lc=eng&pageMode=OV&pid=810708&ct=PRODUCT&id=810708). The calibration kit available is 3.5mm (htt ://www.home.agilent.com/agilent/product jspx?cc=US&lc=eng&pageMode=OV&pid=1 3542%3Aepsg%3Apro&ct=PRODUCT&id=103542%3Aepsg%3Apro). How many ports do I need to connect to (port 1&2, or port 1&2&3)? I start using a VNA two weeks ago and is not familiar with it. As a matter of fact, I used a demo VNA (only two ports http://www.us.anritsu.com/pro ucts/37000D-Series_Lightning-Family-of- icroW-VNAs--Value-Line_ARSPG_ARQQSidZ643.aspx) to calibrate cable loss. Thank you for your time and look forward to hearing from you. Best regards, Grace - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher David Heald - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher David Heald
Re: LISN Calibration
In message <2a93eb060902091158v1946f9d1ye54dc2862aea9...@mail.gmail.com>, dated Mon, 9 Feb 2009, Grace Lin writes: >I have learned from members that ANSI C63.4 and CISPR 16-1-2 are the >calibration standards for LISN for my daily measurement. I have one of >my two LISNs ship out last week to an accredited calibration lab. I >wonder if I need to ship out the other one for calibration since the >second one is used for support equipment. I would strongly advise it. I have found strange differences in results with two apparently good LISNs. This may be why the CISPR 16-1-2 requirements have been made more detailed over the past few years. > Is it sufficient that I verify it in-house? If yes, I would need your >help with calibration. It's always worth knowing how to do it. > >I study A.8 of CISPR 16-1-2 Edition 1.2 and Annex E of ANSI C63.4-2003 >this morning. Here are my questions: > >1. The title of A.8 is "Measurement of the voltage division factor of >an artificial mains V-network". What does "voltage division factor"? >Does it mean insertion loss? Not exactly; it's the ratio of input voltage, at the connector supplying mains power to the EUT to output voltage at the connector for the measuring receiver. Differences in the impedances at these points are not taken into account, so the ratio is not 'insertion loss' as normally defined. A.8 was written by someone who knew the subject very well, so well that it can be very difficult for others to understand. And the requirement for voltage division factor is 'hidden' in the caption of Figure 4.10. >2. Is the adapter, mentioned in Figure A.6a, Figure A.6b of CISPR >16-1-2 and Figure E.1(a) of ANSI C63.4, commercially available? I don't know: I've made mine myself. >If not, is there any guidelines to make it (type of connectors, size >and length of wires/cables, etc.)? I think there is no need to be extremely meticulous about this. Whatever mains connector you use, it is not matched to 50 ohms or anything else, but it is electrically 'short' (compared with a wavelength) even at 30 MHz, so it has little effect. Just keep all connections short and rigid (movement of connections can impair repeatability). >Should I take a pin from a power plug and solder one end to a SMA >receptacle? No. The connections in Figure A6a are **coaxial cables**, so that isn't a single connection to L1 but a coaxial connection to L1 and ground. >If yes, is there any preference for the type of the receptacle (cable >jack, panel jack, bulkhead, etc. >http://www.amphenolrf.com/Products/CatalogPages/sma_catalog.pdf)? Just keep the wires short and rigid, if the connection is not coax. I have, for example, mounted two BNC connectors (L1/ground and N/ground) directly on a metal plate attached to the cover of a UK 13 A plug. I also have a single BNC connected by a short (100 mm)50 ohm coax to a 13 A plug. Inside the plug is a network of five 82 ohm resistors. One goes >from each power pin to the ground pin. The other three are connected as a delta, one apex to each power pin, and the third to the incoming coax inner. The outer of the coax goes to ground, of course. This gives an input impedance close to 50 ohms, and 30 ohms between power pins and >from each power pin to ground (network alone; no generator connected). The insertion loss is 11.2 dB. I don't remember whether someone told me about this arrangement or whether I invented it. With this device, you can look at both outputs of the LISN at once, if the switching allows you access to both outputs simultaneously (as, in my opinion, it should) for direct comparison purposes. >3. How do I terminate the mains port? The LISN, Solar 9252-50-R-24-N >(same as 9252-50-R-24-BNC except with N connector) comes with a >permanent attached power cord. Should I pick up a receptable (no wire >attached) and connect 50 ohms resistor to L and N respectively, and >connect the other end of the resistors to ground reference? That's all you can do without modifying the LISN. You could cut the cable short, fit an in-line IEC 320 free socket to it and use an IEC 320 mains lead in future. Then you would have a terminator consisting of an IEC 320 plug with two parallel pairs of 100 ohm resistors inside, power pins to ground. >4. Is there any requirement (VSWR etc.) for the 50 ohms terminator? Any commercial terminator is most unlikely to have a poor VSWR up to 30 MHz. Even a 51 ohm metal film resistor inside a BNC plug is likely to be OK. >5. Is 10 dB pads needed? Figure A.6a and Figure A.6b of CISPR 16-1-2 >show them. The NOTE from Figure E.1(b) states "Attenuator pads not >used with network analyzer. The pads are there to prevent errors due to mismatched impedances. Your set-up and LISN may or may not need them. You can only tell by measuring with and without to see if the results differ. >6. Figure A.6a and Figure A.6b of CISPR 16-1-2 show two ports of >network analyz
LISN Calibration
Dear Members, I have learned from members that ANSI C63.4 and CISPR 16-1-2 are the calibration standards for LISN for my daily measurement. I have one of my two LISNs ship out last week to an accredited calibration lab. I wonder if I need to ship out the other one for calibration since the second one is used for support equipment. Is it sufficient that I verify it in-house? If yes, I would need your help with calibration. I study A.8 of CISPR 16-1-2 Edition 1.2 and Annex E of ANSI C63.4-2003 this morning. Here are my questions: 1. The title of A.8 is "Measurement of the voltage division factor of an artificial mains V-network". What does "voltage division factor"? Does it mean insertion loss? 2. Is the adapter, mentioned in Figure A.6a, Figure A.6b of CISPR 16-1-2 and Figure E.1(a) of ANSI C63.4, commercially available? If not, is there any guidelines to make it (type of connectors, size and length of wires/cables, etc.)? Should I take a pin from a power plug and solder one end to a SMA receptacle? If yes, is there any preference for the type of the receptacle (cable jack, panel jack, bulkhead, etc. http://www.amphenolrf.com/Products/CatalogPages/sma_catalog.pdf)? 3. How do I terminate the mains port? The LISN, Solar 9252-50-R-24-N (same as 9252-50-R-24-BNC except with N connector) comes with a permanent attached power cord. Should I pick up a receptable (no wire attached) and connect 50 ohms resistor to L and N respectively, and connect the other end of the resistors to ground reference? 4. Is there any requirement (VSWR etc.) for the 50 ohms terminator? 5. Is 10 dB pads needed? Figure A.6a and Figure A.6b of CISPR 16-1-2 show them. The NOTE from Figure E.1(b) states "Attenuator pads not used with network analyzer. 6. Figure A.6a and Figure A.6b of CISPR 16-1-2 show two ports of network analyzer are used. Figure E.1(b) shows three ports of network analyzer are used. The vector network analyzer I have access to comes with four ports (http://www.home.agilent.com/agilent/pr duct.jspx?cc=US&lc=eng&pageMode=OV&pid=810708&ct=PRODUCT&id=810708). The calibration kit available is 3.5mm (htt ://www.home.agilent.com/agilent/product jspx?cc=US&lc=eng&pageMode=OV&pid=1 3542%3Aepsg%3Apro&ct=PRODUCT&id=103542%3Aepsg%3Apro). How many ports do I need to connect to (port 1&2, or port 1&2&3)? I start using a VNA two weeks ago and is not familiar with it. As a matter of fact, I used a demo VNA (only two ports http://www.us.anritsu.com/pro ucts/37000D-Series_Lightning-Family-of- icroW-VNAs--Value-Line_ARSPG_ARQQSidZ643.aspx) to calibrate cable loss. Thank you for your time and look forward to hearing from you. Best regards, Grace - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas Mike Cantwell For policy questions, send mail to: Jim Bacher David Heald
Re: In-house LISN calibration
Hi All, regarding this: ANSI does require the LISNs to be calibrated in the installation it will be used, including any external power socket you may have for plugging in the EUT. We have someone come on-site to do the calibration, but it would be easier to do in-house, so it could be done at any time. I need to calibrate the 250 uH LISNs for 150 kHz to 30 MHz. Before folks jump off the deap end, be aware for the difference between calibration and verification. LISN's need to be calibrated, which means they are checked for their insertion loss, impedance etc. This is done under tightly controlled conditions. What needs to be done when a LISN is installed, is a verification that paramiters are not substantally degraded. An inplace verification is checking that when a LISN is connected to the power source, any impedances in that power source ( eg EMI Room filters ) do not change the LISN behaviour. ALSO, when a cable linking the LISN measurement port is hooked up to the measuring instrument, any component in that measurement path dos not influence the LISN. This should NOT be construed as calibration. Cheers, Derek Walton This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ieee-pses.org/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: emc-p...@hypercom.com Dave Heald: emc_p...@symbol.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
Re: In-house LISN calibration
ANSI does require the LISNs to be calibrated in the installation it will be used, including any external power socket you may have for plugging in the EUT. We have someone come on-site to do the calibration, but it would be easier to do in-house, so it could be done at any time. I need to calibrate the 250 uH LISNs for 150 kHz to 30 MHz. Regards, Tim
RE: In-house LISN calibration
Did you try placing an attenuator between the LISN and the filter? 3 or 6 dB should help. Dave Cuthbert From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org] On Behalf Of Donnelly, Thomas Sent: Thursday, May 06, 2004 5:15 AM To: 'Bill Stumpf'; EMC-PST (E-mail) Subject: RE: In-house LISN calibration As I understand ANSI C63.4 the impedance measurement is required. In fact it is required that you meet the curve when connected to ant EMI filters you would use during a test. At a previous employer this was interpreted as a mandate to calibrate them in house. This really created a nightmare considering that there were 6 chambers and a couple dozen different LISN's. Connecting to a filter does make a difference. In fact we had several LISN's that looked good standalone that did not meet the criteria when connected to the filter. We wound up tuning the LISN's to meet the curve with the filters attached. Anyone else run into this problem? Tom Donnelly Smiths Aerospace Actuation Systems 973-428-9898 x445 tdonne...@act-sys.com From: Bill Stumpf [mailto:bstu...@dlsemc.com] Sent: Wednesday, May 05, 2004 2:50 PM To: 'emcp...@aol.com'; emc-p...@majordomo.ieee.org Subject: RE: In-house LISN calibration Tim, The standard to be used for LISN calibration is ANSI C63.4. The insertion loss can be measured using a spectrum analyzer, but I am not aware of a method to use a spectrum analyzer for the impedance. We use a S-Parameters Network Analyzer. Bill -Original Message- From: emcp...@aol.com [mailto:emcp...@aol.com] Sent: Wednesday, May 05, 2004 12:15 PM To: emc-p...@majordomo.ieee.org Subject: In-house LISN calibration Hello, I have an HP 3589A Spectrum/Network Analyzer. I was wondering if there is any way to do in-house calibration of the LISNs. I need to verify the impedance and the insertion loss of each LISN. I'm not sure if the unit I have will do the job. I need the calibration procedure to be accepted by various agencies (via ANSI C63.4 / CISPR standards). I don't want just a "verification procedure". Anyone know how this can be done? Thanks. Tim Pierce
RE: In-house LISN calibration
As I understand ANSI C63.4 the impedance measurement is required. In fact it is required that you meet the curve when connected to ant EMI filters you would use during a test. At a previous employer this was interpreted as a mandate to calibrate them in house. This really created a nightmare considering that there were 6 chambers and a couple dozen different LISN's. Connecting to a filter does make a difference. In fact we had several LISN's that looked good standalone that did not meet the criteria when connected to the filter. We wound up tuning the LISN's to meet the curve with the filters attached. Anyone else run into this problem? Tom Donnelly Smiths Aerospace Actuation Systems 973-428-9898 x445 tdonne...@act-sys.com From: Bill Stumpf [mailto:bstu...@dlsemc.com] Sent: Wednesday, May 05, 2004 2:50 PM To: 'emcp...@aol.com'; emc-p...@majordomo.ieee.org Subject: RE: In-house LISN calibration Tim, The standard to be used for LISN calibration is ANSI C63.4. The insertion loss can be measured using a spectrum analyzer, but I am not aware of a method to use a spectrum analyzer for the impedance. We use a S-Parameters Network Analyzer. Bill -Original Message- From: emcp...@aol.com [mailto:emcp...@aol.com] Sent: Wednesday, May 05, 2004 12:15 PM To: emc-p...@majordomo.ieee.org Subject: In-house LISN calibration Hello, I have an HP 3589A Spectrum/Network Analyzer. I was wondering if there is any way to do in-house calibration of the LISNs. I need to verify the impedance and the insertion loss of each LISN. I'm not sure if the unit I have will do the job. I need the calibration procedure to be accepted by various agencies (via ANSI C63.4 / CISPR standards). I don't want just a "verification procedure". Anyone know how this can be done? Thanks. Tim Pierce
Re: In-house LISN calibration
I'm beginning to think I'm not sure what you mean by insertion loss. If you use the 50 uH LISN for a mil-std measurement, there is a loss between power output power port and EMI port below 100 kHz that must be accounted for due to the 0.25 uF blocking cap. At and above 150 kHz, it is negligible, although some LISNs use a 0.1 uF blocking cap so that effects the loss up to higher frequencies. If by insertion loss you mean how the LISN departs from looking like 50 Ohms, that will be near zero at 450 kHz and up but not between 150-450 kHz and definitely way off below 150 kHz for the mil-std measurement. From: emcp...@aol.com Reply-To: emcp...@aol.com List-Post: emc-pstc@listserv.ieee.org Date: Wed, 5 May 2004 18:02:50 EDT To: drcuthb...@micron.com, bstu...@dlsemc.com, emc-p...@majordomo.ieee.org Subject: Re: In-house LISN calibration Thanks Dave. ANSI C63.4 looks for the impedance curve (+/- 20% of reference) and the insertion loss (which should be a flat line, as close to zero as possible). I would need to get a bridge or some sort of adapter. Where would I get something like that. Thanks. Tim Pierce
RE: In-house LISN calibration
Tim, the Mini-circuits ZDC-20-3 covers 0.2 to 250 MHz. It is $45. Here is their ap note: www.minicircuits.com/appnote/coup7-2.pdf The Agilent 8721A covers 0.1 to 100 MHz. It runs $453. This one is better and covers the low end where I think you need coverage. Dave From: emcp...@aol.com [mailto:emcp...@aol.com] Sent: Wednesday, May 05, 2004 4:03 PM To: drcuthbert; bstu...@dlsemc.com; emc-p...@majordomo.ieee.org Subject: Re: In-house LISN calibration Thanks Dave. ANSI C63.4 looks for the impedance curve (+/- 20% of reference) and the insertion loss (which should be a flat line, as close to zero as possible). I would need to get a bridge or some sort of adapter. Where would I get something like that. Thanks. Tim Pierce
Re: In-house LISN calibration
Thanks Dave. ANSI C63.4 looks for the impedance curve (+/- 20% of reference) and the insertion loss (which should be a flat line, as close to zero as possible). I would need to get a bridge or some sort of adapter. Where would I get something like that. Thanks. Tim Pierce
Re: In-house LISN calibration
Thanks for your input, Ken. Would this be accepted as a calibrated measurement by various customers & agencies? I want to make sure this measurement would be the equivalent of having a calibration laboratory do it. Thanks. Tim Pierce
Re: In-house LISN calibration
The HP3589 covers the frequency range of 10 Hz to 150 MHz, more than sufficient for the LISN range of 0.01 - 10 MHz. As long as the 3589 is calibrated then I don't see why you can't use it to calibrate the LISNs. It is ideal for use in this application because of the available 1 MOhm input impedance; more on this below. As far as how to do it, there are lots of different ways. You can measure the current into the power output port while measuring the line-to-ground applied potential, and take the ratio. You can measure just the applied potential >from your 50 Ohm source, and from the loading effect you can back out the impedance. If you have a directional coupler (the one for low frequency CS114) you can measure forward and reverse power and infer the impedance from that. If you separately first measure the insertion loss due to the blocking cap between power output and EMI port, then you can measure applied potential at the EMI port and accounting for the blocking cap you can measure the loading effect of the LISN and back out the impedance again. Of all these techniques, if I were doing it, I would get my handy Solar 6741 current probe (the one with FLAT transfer impedance from 10 kHz to 30 MHz) and use its output as the network analyzer reference port input. The applied potential from the LISN output port to ground would be my test input. You will want to use the VERY convenient 1 MOhm input so you don't load the potential measurement. The network analyzer would be set to display the ratio of test port to reference port. That ratio, plus 3 dB Ohms (the inverse of the current probe -3 dB Ohm transfer impedance) is the impedance of the LISN. Ken Javor From: emcp...@aol.com Reply-To: emcp...@aol.com List-Post: emc-pstc@listserv.ieee.org Date: Wed, 5 May 2004 13:15:19 EDT To: emc-p...@majordomo.ieee.org Subject: In-house LISN calibration Hello, I have an HP 3589A Spectrum/Network Analyzer. I was wondering if there is any way to do in-house calibration of the LISNs. I need to verify the impedance and the insertion loss of each LISN. I'm not sure if the unit I have will do the job. I need the calibration procedure to be accepted by various agencies (via ANSI C63.4 / CISPR standards). I don't want just a "verification procedure". Anyone know how this can be done? Thanks. Tim Pierce
RE: In-house LISN calibration
Does ANSW C63.4 call for the complex impedance, or just the magnitude of the reflection coefficient, or the return loss? If the latter, then a spectrum analyzer, a signal source, and a return loss bridge would work. I assume the three items need current calibrations and that an error analysis needs to be performed. Sounds easier to send the LISN to a certified cal lab. Dave Cuthbert Micron Technology From: owner-emc-p...@majordomo.ieee.org [mailto:owner-emc-p...@majordomo.ieee.org] On Behalf Of Bill Stumpf Sent: Wednesday, May 05, 2004 12:50 PM To: 'emcp...@aol.com'; emc-p...@majordomo.ieee.org Subject: RE: In-house LISN calibration Tim, The standard to be used for LISN calibration is ANSI C63.4. The insertion loss can be measured using a spectrum analyzer, but I am not aware of a method to use a spectrum analyzer for the impedance. We use a S-Parameters Network Analyzer. Bill -Original Message- From: emcp...@aol.com [mailto:emcp...@aol.com] Sent: Wednesday, May 05, 2004 12:15 PM To: emc-p...@majordomo.ieee.org Subject: In-house LISN calibration Hello, I have an HP 3589A Spectrum/Network Analyzer. I was wondering if there is any way to do in-house calibration of the LISNs. I need to verify the impedance and the insertion loss of each LISN. I'm not sure if the unit I have will do the job. I need the calibration procedure to be accepted by various agencies (via ANSI C63.4 / CISPR standards). I don't want just a "verification procedure". Anyone know how this can be done? Thanks. Tim Pierce
RE: In-house LISN calibration
Tim, The standard to be used for LISN calibration is ANSI C63.4. The insertion loss can be measured using a spectrum analyzer, but I am not aware of a method to use a spectrum analyzer for the impedance. We use a S-Parameters Network Analyzer. Bill -Original Message- From: emcp...@aol.com [mailto:emcp...@aol.com] Sent: Wednesday, May 05, 2004 12:15 PM To: emc-p...@majordomo.ieee.org Subject: In-house LISN calibration Hello, I have an HP 3589A Spectrum/Network Analyzer. I was wondering if there is any way to do in-house calibration of the LISNs. I need to verify the impedance and the insertion loss of each LISN. I'm not sure if the unit I have will do the job. I need the calibration procedure to be accepted by various agencies (via ANSI C63.4 / CISPR standards). I don't want just a "verification procedure". Anyone know how this can be done? Thanks. Tim Pierce
In-house LISN calibration
Hello, I have an HP 3589A Spectrum/Network Analyzer. I was wondering if there is any way to do in-house calibration of the LISNs. I need to verify the impedance and the insertion loss of each LISN. I'm not sure if the unit I have will do the job. I need the calibration procedure to be accepted by various agencies (via ANSI C63.4 / CISPR standards). I don't want just a "verification procedure". Anyone know how this can be done? Thanks. Tim Pierce
Re: LISN Calibration
I read in !emc-pstc that Chris Maxwell wrote (in <83d652574e7af740873674f9fc12dbaa675...@utexh1w2.gnnettest.com>) about 'LISN Calibration', on Fri, 30 Nov 2001: >reference CISPR 16 or EN 55016 I don't think there is an EN55016. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: LISN Calibration
I read in !emc-pstc that Patrick Lawler wrote (in <5sef0uc2qlad6kdjq2fi0e0v76ju6vj...@4ax.com>) about 'LISN Calibration', on Fri, 30 Nov 2001: >I ran into that exact problem (a floating power source) a few years ago. Anyone who benefited from the 'Rational Manger' or 'Kepner-Tregoe' training course will recognise this. *Anything* that is changed can have 'unexpected' effects, if you don't actively look for them. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: LISN Calibration
John's concern (see attached email at the end) is on target, but there is a solution. I have the isolation transformer wired so that line and neutral from the wall outlet connect to the primary side. The windings ratio then provides a step-up so that I get 230VAC across the secondary (this is so that I test with "European" voltage). Ground makes no connection on the primary side. On the secondary side, I tie ground to one side of the secondary winding. This terminal is then wired as "neutral" in the isolation transformer's output cord. Even though ground and neutral are tied together at the secondary, I use a three wire output cord for the secondary output. The output is wired as a "hot" (Brown), "Earth" (Green/Yel) and an "Earthy neutral" (Blue).I didn't invent this, I have seen it in some test setup literature and it is recommended in the Keytek CE Master manual. (The manual has a section on operating the unit behind an isolation transformer). It appears to work for LISNs as well. LISNs, by nature have a mains filter (reference CISPR 16 or EN 55016). In my case, the LISNs integral filter just wasn't enough. The copier in the other room was just too darn noisy. I couldn't get a clean measurement to save my life until we hooked up the isolation transformer. From John's email it appears that his solution was to use additional mains filtering (using components other than an isolation transformer) this sounds like another perfectly good solution. Measurements with our isolation transformer - LISN setup seem to be repeatable when compared to outside lab measurements. We just used this to troubleshoot and correct a failure measured at an outside lab (hi guys, you know who you are) within the past couple of weeks. This is only my experience, others may see a drawback to this method. As always, when you're messing with AC, be CAREFUL. Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | > -Original Message- > From: John Woodgate [SMTP:j...@jmwa.demon.co.uk] > Sent: Thursday, November 29, 2001 12:44 PM > To: emc-p...@majordomo.ieee.org > Subject: Re: LISN Calibration > > > I read in !emc-pstc that Peters, Michael wrote > (in <61c1e83d9da9d311a871009027d617f001632...@peaexch1.analogic.com>) > about 'LISN Calibration', on Thu, 29 Nov 2001: > >If you have not already done so, I would recommend an isolation > transformer. > >Many factories and office buildings have a great deal of ambient > noise that > >will interfere with your measurements. > > That could be a bit problematic. The LISN was designed to work with > normal mains supplies, in which the neutral is earthed or earthy. You > may not get the same results with a floating supply. > > My LISN has a mains filter on the incoming supply. CISPR16-1 mentions > that this may be necessary and, by implication, allows it. > -- > Regards, John Woodgate, OOO - Own Opinions Only. > http://www.jmwa.demon.co.uk > After swimming across the Hellespont, I felt like a Hero. > --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: LISN Calibration
I ran into that exact problem (a floating power source) a few years ago. The conducted emissions test results on a power supply at an outside lab were 4-5dB higher than our precompliance bench in-house. I sent the LISN's back to the manufacturer for performance verification, and they were fine. I took the spectrum analyzer to the outside lab to compare its performance to their equipment, and the results matched. I finally realized the only difference between the test setups was the source of power: labs fed their LISNs directly from a wall outlet (with grounded neutral), while we fed ours from a variac followed by an isolation tranformer. Out of frustration, I connected our LISNs directly to a wall outlet. The conducted emissions readings finally agreed! It turns out the filter in the switching power supply had differing values of EMI capacitors from primary to chassis (after the rectifier), and using a grounded source at the LISN input degraded its performance. Patrick Lawler plaw...@west.net On Thu, 29 Nov 2001 17:43:35 +, John Woodgate wrote: >I read in !emc-pstc that Peters, Michael wrote >(in <61c1e83d9da9d311a871009027d617f001632...@peaexch1.analogic.com>) >about 'LISN Calibration', on Thu, 29 Nov 2001: >>If you have not already done so, I would recommend an isolation transformer. >>Many factories and office buildings have a great deal of ambient noise that >>will interfere with your measurements. > >That could be a bit problematic. The LISN was designed to work with >normal mains supplies, in which the neutral is earthed or earthy. You >may not get the same results with a floating supply. > >My LISN has a mains filter on the incoming supply. CISPR16-1 mentions >that this may be necessary and, by implication, allows it. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: LISN Calibration
I read in !emc-pstc that Peters, Michael wrote (in <61c1e83d9da9d311a871009027d617f001632...@peaexch1.analogic.com>) about 'LISN Calibration', on Thu, 29 Nov 2001: >If you have not already done so, I would recommend an isolation transformer. >Many factories and office buildings have a great deal of ambient noise that >will interfere with your measurements. That could be a bit problematic. The LISN was designed to work with normal mains supplies, in which the neutral is earthed or earthy. You may not get the same results with a floating supply. My LISN has a mains filter on the incoming supply. CISPR16-1 mentions that this may be necessary and, by implication, allows it. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: LISN Calibration
Hi Joe, I made a homemade LISN using a schematic from Clayton R Paul's book. Our company also bought a pre-compliance LISN from Wayne Kerr. In my experience, both are good enough for pre-compliance work. My "calibration" is done by measuring products that were previously tested at an outside lab. I compare my actual results with thiers. The only bad part about this is that you need a product with a failing or near failing emissions profile to get a good "comb" of data for comparison. Fortunately we had a power suppy about 4 years ago with a 150Khz switching frequency and a slightly failing emissions profile. It produced a beautiful set of harmonics at the lab. So, I calibrated my setup while I troubleshot this power supply. This comparison gives me a rough confidence factor in the setup. No it's not a calibration sticker; but I'll take an actual comparison over a cal sticker any day. I second Michael's opinion regarding the isolation transformer. Our measurements were erroneous and noisy (the copier in the other room produced so much conducted noise that I couldn't see anything from the DUT) until I bought an Isolation Transformer. We bought a Panel Components part # 82520030. It has served us well. It offers the option to wire it up for a 2:1 ratio, so I use it to create 230VAC for European products. I would also like to add that I use our ESD bench as a pre-compliance conducted emissions setup. It already has a ground plane. I tie the LISN's ground to this plane as a reference. Seems to work well. So I guess that a hunk of metal for a ground plane is a recommended purchase. Other items that have proven to be valuable are various line cords with ends cut and stripped. These can be used along with wire nuts to quickly allow your LISN to test products with different line cords ... There are tricks to wiring ground through the isolation transformer, wiring DC through your LISN (for DC products) ... it doesn't take a great deal of money or time to set up for pre-compliance. Have fun and don't kill yourself!!! Chris Maxwell | Design Engineer - Optical Division email chris.maxw...@nettest.com | dir +1 315 266 5128 | fax +1 315 797 8024 NetTest | 6 Rhoads Drive, Utica, NY 13502 | USA web www.nettest.com | tel +1 315 797 4449 | > -Original Message- > From: Peters, Michael [SMTP:mpet...@analogic.com] > Sent: Thursday, November 29, 2001 8:58 AM > To: 'marti...@appliedbiosystems.com'; emc-p...@majordomo.ieee.org > Subject: RE: LISN Calibration > > > Joe, > > For piece of mind. The LISN provides repeatable results for different > line > impedances. Making sure that the LISN impedance is what it is > supposed to > be and the insertion loss is satisfactory will give you a better > comfort > level when going to the test house. > > If you have not already done so, I would recommend an isolation > transformer. > Many factories and office buildings have a great deal of ambient noise > that > will interfere with your measurements. > > If you have an s-parameter network analyzer (that works from 150 kHz > to 30 > MHz), the calibration is not too difficult to perform and there is a > procedure outlined in ANSI C63.4 that is easy enough to follow > (although for > impedance it doesn't mention you need an RF splitter). > > Good Luck! > > Michael Peters > mpet...@ieee.org > > -Original Message- > From: marti...@appliedbiosystems.com > [mailto:marti...@appliedbiosystems.com] > Sent: Wednesday, November 28, 2001 7:16 PM > To: emc-p...@majordomo.ieee.org > Subject: LISN Calibration > > > > We are in the process of setting up a pre-compliance EMC lab. One of > the > tests that we will be performing is pre-compliance conducted emissions > per > EN 61326. > > I realize that since we are only performing pre-compliance > measurements > that calibration of the LISN is not required. However, do you > recommend > calibrating the LISN for pre-compliance measurements? If so, why? > > Your responses are appreciated > > Regards > > Joe Martin > Applied Biosystems > > > > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute:
Re: LISN Calibration
I read in !emc-pstc that marti...@appliedbiosystems.com wrote (in ) about 'LISN Calibration', on Wed, 28 Nov 2001: >I realize that since we are only performing pre-compliance measurements >that calibration of the LISN is not required. However, do you recommend >calibrating the LISN for pre-compliance measurements? If so, why? Well, you certainly need to know that it is working and not giving you results that are 10 dB or more in error! The procedure in F.8 of CISPR16-1 is much better that was originally proposed, which I complained loudly was incomprehensible, but it is still rather more complicated than necessary. You don't need a network analyser: a signal generator and a spectrum analyser or calibrated receiver will do quite well. Is this a purchased LISN or did you make your own? The constructional details in CISPR16-1 are also vastly over-complicated - that huge inductor is just crazy unless you really need it to carry 25 A. I made one that will carry 10A without overheating for quite long enough to do a test, and compares in performance quite well with a purchased product. -- Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk After swimming across the Hellespont, I felt like a Hero. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: LISN Calibration
There is nothing to "go bad" in a LISN if it hasn't been physically damaged, which should be obvious by inspection. If there is any concern, a spot check or insertion loss sweep with a tracking generator or a sig gen is perfectly okay for assessing LISN performance. And the analyzer/generator need not be calibrated either - the chance that all three devices are off by the same amount are vanishingly small. on 11/29/01 6:40 AM, Sundstrom Michael (NMP-RD/Dallas) at michael.sundst...@nokia.com wrote: > > The only problem I see with not calibrating the LISN is you wouldn't > know if / or when it goes bad until you cross check it with a calibrated > LISN. > > I would suggest you run your precompliance lab just like the real lab. > This way you'll get the same results as the accredited lab you test > with. No surprises this way. > > Michael Sundstrom > NOKIA > TCC Dallas / EMC > ofc: (972) 374-1462 > cell: (817) 917-5021 > amateur call: KB5UKT > > > -Original Message- > From: ext Ken Javor [mailto:ken.ja...@emccompliance.com] > Sent: Wednesday, November 28, 2001 9:06 PM > To: marti...@appliedbiosystems.com; emc-p...@majordomo.ieee.org > Subject: Re: LISN Calibration > > > > I would say that if it came calibrated from the manufacturer and has not > suffered visible damage it should be okay. It is easy to check a few > spot > frequencies or use a spectrum analyzer with tracking generator or > separate > sweeping sig gen to check performance. Either way it is not a big deal. > > on 11/28/01 4:15 PM, marti...@appliedbiosystems.com at > marti...@appliedbiosystems.com wrote: > >> >> We are in the process of setting up a pre-compliance EMC lab. One of > the >> tests that we will be performing is pre-compliance conducted emissions > per >> EN 61326. >> >> I realize that since we are only performing pre-compliance > measurements >> that calibration of the LISN is not required. However, do you > recommend >> calibrating the LISN for pre-compliance measurements? If so, why? >> >> Your responses are appreciated >> >> Regards >> >> Joe Martin >> Applied Biosystems >> >> >> >> >> --- >> This message is from the IEEE EMC Society Product Safety >> Technical Committee emc-pstc discussion list. >> >> Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ >> >> To cancel your subscription, send mail to: >> majord...@ieee.org >> with the single line: >> unsubscribe emc-pstc >> >> For help, send mail to the list administrators: >> Michael Garretson:pstc_ad...@garretson.org >> Dave Healddavehe...@mediaone.net >> >> For policy questions, send mail to: >> Richard Nute: ri...@ieee.org >> Jim Bacher: j.bac...@ieee.org >> >> All emc-pstc postings are archived and searchable on the web at: >> No longer online until our new server is brought online and the old > messages >> are imported into the new server. >> > > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old > messages are imported into the new server. > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable o
RE: LISN Calibration
The only problem I see with not calibrating the LISN is you wouldn't know if / or when it goes bad until you cross check it with a calibrated LISN. I would suggest you run your precompliance lab just like the real lab. This way you'll get the same results as the accredited lab you test with. No surprises this way. Michael Sundstrom NOKIA TCC Dallas / EMC ofc: (972) 374-1462 cell: (817) 917-5021 amateur call: KB5UKT -Original Message- From: ext Ken Javor [mailto:ken.ja...@emccompliance.com] Sent: Wednesday, November 28, 2001 9:06 PM To: marti...@appliedbiosystems.com; emc-p...@majordomo.ieee.org Subject: Re: LISN Calibration I would say that if it came calibrated from the manufacturer and has not suffered visible damage it should be okay. It is easy to check a few spot frequencies or use a spectrum analyzer with tracking generator or separate sweeping sig gen to check performance. Either way it is not a big deal. on 11/28/01 4:15 PM, marti...@appliedbiosystems.com at marti...@appliedbiosystems.com wrote: > > We are in the process of setting up a pre-compliance EMC lab. One of the > tests that we will be performing is pre-compliance conducted emissions per > EN 61326. > > I realize that since we are only performing pre-compliance measurements > that calibration of the LISN is not required. However, do you recommend > calibrating the LISN for pre-compliance measurements? If so, why? > > Your responses are appreciated > > Regards > > Joe Martin > Applied Biosystems > > > > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old messages > are imported into the new server. > --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
RE: LISN Calibration
Joe, For piece of mind. The LISN provides repeatable results for different line impedances. Making sure that the LISN impedance is what it is supposed to be and the insertion loss is satisfactory will give you a better comfort level when going to the test house. If you have not already done so, I would recommend an isolation transformer. Many factories and office buildings have a great deal of ambient noise that will interfere with your measurements. If you have an s-parameter network analyzer (that works from 150 kHz to 30 MHz), the calibration is not too difficult to perform and there is a procedure outlined in ANSI C63.4 that is easy enough to follow (although for impedance it doesn't mention you need an RF splitter). Good Luck! Michael Peters mpet...@ieee.org -Original Message- From: marti...@appliedbiosystems.com [mailto:marti...@appliedbiosystems.com] Sent: Wednesday, November 28, 2001 7:16 PM To: emc-p...@majordomo.ieee.org Subject: LISN Calibration We are in the process of setting up a pre-compliance EMC lab. One of the tests that we will be performing is pre-compliance conducted emissions per EN 61326. I realize that since we are only performing pre-compliance measurements that calibration of the LISN is not required. However, do you recommend calibrating the LISN for pre-compliance measurements? If so, why? Your responses are appreciated Regards Joe Martin Applied Biosystems --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server. --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
Re: LISN Calibration
I would say that if it came calibrated from the manufacturer and has not suffered visible damage it should be okay. It is easy to check a few spot frequencies or use a spectrum analyzer with tracking generator or separate sweeping sig gen to check performance. Either way it is not a big deal. on 11/28/01 4:15 PM, marti...@appliedbiosystems.com at marti...@appliedbiosystems.com wrote: > > We are in the process of setting up a pre-compliance EMC lab. One of the > tests that we will be performing is pre-compliance conducted emissions per > EN 61326. > > I realize that since we are only performing pre-compliance measurements > that calibration of the LISN is not required. However, do you recommend > calibrating the LISN for pre-compliance measurements? If so, why? > > Your responses are appreciated > > Regards > > Joe Martin > Applied Biosystems > > > > > --- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ > > To cancel your subscription, send mail to: > majord...@ieee.org > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Michael Garretson:pstc_ad...@garretson.org > Dave Healddavehe...@mediaone.net > > For policy questions, send mail to: > Richard Nute: ri...@ieee.org > Jim Bacher: j.bac...@ieee.org > > All emc-pstc postings are archived and searchable on the web at: > No longer online until our new server is brought online and the old messages > are imported into the new server. > --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
LISN Calibration
We are in the process of setting up a pre-compliance EMC lab. One of the tests that we will be performing is pre-compliance conducted emissions per EN 61326. I realize that since we are only performing pre-compliance measurements that calibration of the LISN is not required. However, do you recommend calibrating the LISN for pre-compliance measurements? If so, why? Your responses are appreciated Regards Joe Martin Applied Biosystems --- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Michael Garretson:pstc_ad...@garretson.org Dave Healddavehe...@mediaone.net For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org All emc-pstc postings are archived and searchable on the web at: No longer online until our new server is brought online and the old messages are imported into the new server.
